1. Field of the Invention
The invention relates to a monoclonal antibody directed against the human tyrosine kinase receptor FLT3/FLK2.
The tyrosine kinase receptor FLT3/FLK2 plays an important role in early hematopoiesis. It naturally occurs in blood stem cells and early lymphoid and myeloid blood progenitor cells and interacts with a growth factor FLT3-ligand (FL), that particularly stimulates the recruitment and proliferation of these cells (Matthews et al., Cell 65:1143, 1991; Small et al., Proc. Natl. Acad. Sci. USA 91:459, 1994; Lyman et al., Blood 83:2795, 1994; Muench et al., Blood 85:963, 1995; Hannum et al., Nature 368:643, 1994; Hirayama et al., Blood 85:1762, 1995).
2. Description of the Related Art
The indirect detection mediated by an antibody specifically binding to the receptor represents a safe and quick method to qualitatively and quantitatively detect membrane bound receptors. The specific antibody can be labeled either directly or indirectly, using this label for identification and quantitative determination of the antibody or the bound receptor, respectively. Particularly, fluorescent dyes or radioactive agents can be used as labels.
Such an antibody can also be coupled to special therapeutically active agents and therefore renders possible a targeted cellular treatment, which is particularly required for the treatment of tumorous diseases.
Antibodies directed against FLT3/FLK2 receptor protein have already been described, however, these antibodies are directed against the murine FLT3/FLK2 receptor protein. Therefore, lacking the required specificity, these antibodies are not suitable for the treatment of human cells.
A monoclonal antibody binding specifically to the native unmodified human FLT3/FLK2 receptor protein, is produced and released by hybridoma cells that were deposited on Dec. 6, 1997 at the International Depository Authority DSMZ-Deutsche Sammlung Von Mikroorganismen Und Zellkulturen Gmbh (German Collection of Microorganisms and Cell Cultures, Ltd. (DSMZ)), Mascheroder Weg 1b, D-38124 Braunschweig Germany under No. DSM ACC2248 at the German Collection of Microorganisms and Cell Cultures Ltd. (DSMZ) in accordance with the provision of the Budapest Treaty. It has been given the designation BV10A4H2. This antibody is subject matter of German Patent DE 196 08 769 titled "antibody BV10A4H2".